Prior to the USS Enterprise-D's first encounter with the Borg, the Federation had little knowledge of their existence, based on encounters with surviving members of species that had been destroyed by them (such as the El-Aurians). However, empirical data on the Borg was very scarce. For example, there were descriptions of cube-shaped vessels, but no information on what Borg individuals looked like, other than rumors that they were cybernetically enhanced.

The Hansens designed new technologies to allow themselves to study the Borg more closely and prevent the Borg from detecting them. They developed multi-adaptive shielding that made the Raven virtually invisible to Borg sensors, and bio-dampeners to mask their bio-signs while on Borg vessels. Magnus visited Borg cubes in person to observe first-hand the behavior and interactions of drones. He and Erin also transported regenerating drones onto the Raven for study. The Hansens became very well-versed and comfortable in their endeavor, even giving them nicknames such as "Junior" and "Needle Fingers." They continued exploration of the Borg for over three years, collecting ten million teraquads of data.

Then, in 2356 on stardate 32634.9, the mission came to a disastrous end. A subspace particle storm damaged the Raven's multi-adaptive shielding, putting it off-line for 13.2 seconds. The Borg detected the Raven and deemed it a threat. Pursuit of the Raven began and attempts to escape them by masking the ship's warp trail failed. The Borg caught the ship and assimilated the Hansens and their daughter, who later became known as Seven of Nine. The Raven itself was partially assimilated, but the Borg chose not to keep it, and it eventually crash landed on an M-classmoonorbiting the fifth planet of a yellow dwarfstar in the region controlled by the species known as the B'omar. The Hansens' field notes, contained in 9,000-plus log entries, were retrieved in 2374 by the FederationstarshipUSS Voyager from the wreckage of the Raven. (VOY: "The Raven")

Unlike her husband, the drone that used to be Erin Hansen was never seen.

Erin Hansen's appearance in "Scorpion, Part II" was not scripted, with the shooting script of "The Raven" being the first teleplay to feature the character. The script of "Dark Frontier" describes Erin Hansen much more significantly than "The Raven"'s script, however, introducing her by stating, "She looks early to mid-thirties, has a dry sense of humor and an astronomical I.Q."